Oh? Maybe I was looking up the wrong thing. Now that I search again I think this is what I was trying to do:

http://stackoverflow.com/questions/30422177/lifetime-in-iter...

though in my case I had a vec of &str or something like that.

What I do remember was the compiler sending me in circles. Honestly if it had just said something like "Hey dummy, you can't do that, go read the chapters on lifetimes again" I might have fixed it. But it kept telling me things like "Just add a lifetime specifier on this line" and I would do that and then get 2 more error messages. I think the errors sent me down the path of trying to do what the SO post mentions, which is

  fn next<'a>(&'a mut self) -> Option<Vec<&'a T>>

instead of putting the lifetime on the impl block, which probably never even occurred to me was something you could do.